As a method of detecting a virus in a biological sample such as blood or the like, there is a method of detecting the gene of the virus by amplification. However, since the biological sample often contains a substance inhibiting of gene amplification, the biological sample has been applied with pretreatment to remove or inactivate the inhibition substance prior to the gene amplification. As the pretreatment method, for example, there is a method of performing purification by a solid-phase carrier or an ion-exchange resin after treating the biological sample with a surfactant, a chaotropic agent, or the like or by heating (Patent Documents 1 to 3). However, these methods require special apparatuses and plural operation steps and therefore are complicated.
Especially, in the detection of the virus whose gene is RNA, since amplification is performed after converting an RNA gene to DNA by a reverse transcriptase, a ribonuclease (RNase) and a reverse transcriptase-inactivating substance also need to be removed or inactivated. Therefore, conventional pretreatment methods further require complicated operations. As the pretreatment method of the biological sample that contains RNA virus, for example, addition of polyamine or sulfated polysaccharides has been known (Patent Document 4). However, the addition of polyamine or sulfated polysaccharides has the possibility of complicating the pretreatment and of causing the polyamine and sulfated polysaccharides to be bonded to the RNA gene and the DNA generated by the reverse transcriptase; and therefore the addition of polyamine or sulfated polysaccharides has the possibility of inhibiting the gene amplification.
The influenza virus is a kind of RNA virus, and the determination of whether the influenza virus is novel or seasonal is clinically very important. As the biological sample for detecting the influenza virus, the rhinal mucosa is commonly used. The detection of the influenza virus should be performed at a clinical practice. Therefore, the establishment of a prompt and simple detection method of influenza virus using the human rhinal mucosa is desired. Such a demand is not limited to the influenza virus and the establishment of such a method is also demanded to general RNA virus detection. Further, the establishment of such a method is demanded not only to the detection of the RNA virus but also to the detection of RNA itself other than the gene.